PROJECT SUMMARY/ABSTRACT Although the link between depression in mothers and their children is well established, little is known about the specific mechanisms by which this risk is conferred. There is growing evidence that children?s biased attention to facial displays of emotion ? specifically, attentional avoidance of sad faces ? may represent a key mechanism of risk that develops early in life. There is growing evidence that these biases develop as early as infancy, with evidence that infants of depressed mothers look less at their mothers? faces, as well as sad facial expressions more generally, than infants of never depressed mothers. This attentional avoidance has been proposed as an emotion regulation strategy in which looking at a depressed mother is upsetting to the infant and shifting their gaze away from their mother then reduces their arousal and negative affect. This negatively reinforces the attentional avoidance which, although potentially adaptive in the short term, is likely to increase risk for depression in the future. To date, however, no study has tested this key hypothesis that the attentional avoidance of sad faces observed in infants of depressed mothers serves to regulate infants? arousal. The goal of this project is to provide a fine-grained test of this hypothesis while also addressing other key gaps in the literature. For example, although the majority of research focuses on the impact of maternal depression on infant outcomes, there are likely bidirectional influences between mothers and their infants. The proposed study will examine these bidirectional influences at multiple units of analysis including affect, behavior, attention, and physiology. The study will include 150 women and their 6-12-month-old infants. Half of the mothers will meet criteria for current major depressive disorder and the other half will be lifetime free of any depressive disorder. Specific Aim 1 is to conduct a multi-method assessment of attention biases in infants of depressed mothers using a combination of mother-infant interaction and computer-based tasks. Specific Aim 2 is to examine infants? arousal as a mechanism underlying their attentional avoidance of sad faces. To do this, we will measure dynamic changes in infants? physiological activity during the interaction tasks. Specific Aim 3 is to examine potential bidirectional influences in affect, behavior, attention, and physiology between mothers and their infants. Our goal is for this research to lead to a more detailed understanding of the mechanisms by which maternal depression may impact children?s attention to facial displays of emotion, which is implicated not only in future depression risk but is also important for infants? broader social and emotional functioning throughout life.